Copper sulfate as draw solute in forward osmosis desalination

Exploring an innovative surfactant and phosphate-based draw solution for forward osmosis desalination

“…Zhao and Zou [47] showed that when the solution against the membrane support layer had a lower aqueous diffusivity but higher viscosity, the ICP phenomenon will be more severe, resulting in lower water flux. According to Alnaizy et al [29], the experimental water flux was observed to be 7 times lower than the ideal water flux. Similarly, reverse salt flux increased slightly when the draw solution concentration was increased because of the increased amount of free Na þ ions in the draw solution.…”

“…For example, monovalent salts (NaCl, KCl, KBr, KNO 3 , NH 4 Cl, KHCO 3 , NaHCO 3 , NH 4 HCO 3 ) with favorable water solubility are frequently used, but the greatest disadvantage of using these salts as a draw solution for FO is the extremely high salt leakage (reverse salt flux reached 29.2 g/m 2 h when using 0.88 M KBr as a draw solution) [25][26][27]. To overcome this problem, divalent (CaSO 4 , MgSO 4 , CuSO 4 , MgCl 2 , CaCl 2 ) and trivalent salts (Al 2 (SO 4 ) 3 , EDTA-2Na) were proposed as draw solutions [26,[28][29][30]. Compared with monovalent salts, the reverse salt fluxes of divalent and trivalent salts were lower because of the larger hydrated radius and higher electrostatic repulsion.…”

Water desalination by forward (direct) osmosis phenomenon: A comprehensive review

“…The membrane exhibits a salt rejection of over 95% [84,90] and has a water permeability coefficient (A) of 3.07 × 10 −12 ms −1 Pa −1 [84]. Since its development and availability, many researchers have used the membrane for FO desalination [18,84,90,128,129]. However, researchers have also synthesized FO membranes in the laboratory a summary of which is provided in Table 1 .…”

“…Similarly, Alnaizy et al used the method of metathesis precipitation to separate the draw solute from pure product water without using energy. In their studies, two draw solutes, copper sulfate [128] and magnesium sulfate [129], were used to desalinate brackish and seawater. Schematic diagram for the FO desalination method utilizing copper sulfate draw solution is shown in Fig.…”

A new class of draw solutions for minimizing reverse salt flux to improve forward osmosis desalination

“…During the last few years, most studies have investigated the used of inorganic salts as draw solutions due to their low cost and high osmotic pressure potential, which creates a high water flux (Achilli et al, 2010;Alnaizy et al, 2013). However, the low charge and small hydrated radius of monovalent and divalent ions in the draw solution can result in a high reverse flux of salts, such as 0.6 M NaCl (J s = 7.2 GMH), 0.6 M NH 4 HCO 3 (J s = 18.2 GMH), or 0.5 M MgCl 2 (J s = 5.6 GMH), when deionized (DI) water was used as the feed solution (Kiriukhin and Collins, 2002).…”